1. Field of the Invention
The present invention generally relates to an electrical card connector, and in particular to an electrical card connector having an improved shell.
2. Description of Related Art
As the popularity of notebook computers increases, integrated circuit (IC) cards are becoming more common for increasing storage capacity or for interfacing the notebook computers with other devices. Electrical card connectors are commonly used to connect motherboards of the computers with the cards. Usually, the electrical card connector includes a shell which can electrically connect with an outer face of the IC card and perform electrostatic discharge (ESD) function.
As disclosed in U.S. Pat. No. 6,475,005, an electrical card connector comprises an insulative housing and a shell covering on the insulative housing, the shell and the insulative housing combine to define a receiving room for receiving a card. The shell has a pair of sidewalls and the front end of each sidewall, which is close to an opening of the receiving room, provides a stamped spring arm bending inwardly. When inserting the card into the electrical card connector, the spring arm can electrically connect with the outer face of the card so as to perform ESD function by a grounding plate of the electrical card connector connected with a printed circuit board (PCB). Another example disclosed in U.S. App. No. 2002/0102882 provides a card connector device which comprises a box shaped frame and a metal cover mounted on the frame. The cover has an upper plate providing three elastic pieces, which not only perform ESD function but also increase the contact between the card connector and an inserted card by the elastic pieces pressing downwardly against the card.
However, if a card connector allows two or more cards different in shapes and sizes to be simultaneously inserted therein, some cards may become positional excursion for being asymmetrically pressed by elastic pieces which perform ESD function provided on a shell of the card connector. As a result, the electrical connection between the card and the card connector may be not good and further the quality of the signal transmission may be not good.